1. Field of the Invention
The present invention relates generally to telephone systems and, more particularly, to a method and apparatus for authorizing a calling card telephone call.
2. Description of the Related Art
The use of telephone calling cards is well known. For example, a customer may receive a telephone card that authorizes telephone call charges to be charged to the customer's account. Typically, the user has to dial a number associated with the calling card processing service and is prompted to dial-in an account number and a personal identification number (PIN) for authentication and authorization purposes. Once the authorization and authentication step is complete, the caller is prompted to dial the called party's telephone number and charges for the call are charged to the customer's account. These types of calling card are susceptible to fraud if the account number and the PIN are disclosed to unauthorized users. One well known fraud technique is to monitor a person making a call using a calling card. By monitoring and recording the numbers being dialed into the phone, a person can determine the numbers which need to be dialed to gain access to the account and thus can make unauthorized telephone calls using the account.
One technique for combating this type of fraud requires the use of a specialized phone having a magnetic card reader. The account and PIN information is embedded in a magnetic strip on the calling card. When a card holder wants to use the calling card, the card is inserted into the magnetic card reader and the account and PIN information can be read. This method of automatically reading the account and PIN information obviates the necessity of the user having to dial this information using the key pad. Therefore, the account and PIN information is not inadvertently disclosed to a third person monitoring the use of the phone by a user. A major disadvantage to this technique, however, is that this calling card can only be used with phones having the capability to read the magnetic strip and it is possible for local phone listening devices to record the account number and pin when the phone converts the magnetic card reader information to dual tone multi-frequency (DTMF) tones, which are sent over the phone line.
Accordingly, there exists a need in the art for a method and apparatus for authorizing a calling card telephone call that prevents fraud and does not require specialized telephone equipment to use.